Revealing mistake: When Bluto is watching the sorority girls have their pillow fight and he falls down with the ladder, you can see him land on a grass mat that is cut into the lawn. It's funny because you can see the grass push in. (00:40:00)
Revealing mistake: In the scene where the Mayor is giving his speech just before the parade begins, there is a man sitting in the bleachers behind him making bizarre faces and hilarious facial ticks in plain view of the camera. (01:34:05)
Revealing mistake: In the parade scene, not only are people wearing long hair and bellbottoms, but late '70s vehicles can be seen passing or parked in the background. Also in one shot, behind the marching ROTC, a camera rig can be seen in front of spectators photographing the parade.
Revealing mistake: When Bluto uses the banner to jump from the building, you can plainly see that his weight is being supported by a safety rope and NOT the banner itself, which is actually slack during the stunt. (01:48:25)
Revealing mistake: After the Deathmobile ramming, when all the grandstand participants are in the heap of broken two by fours, you can see several chainsaw gashes in the structure made by the crew in order to pre-weaken the grandstand and facilitate its collapse.
Revealing mistake: In the scene where Babs is writing down what is said during the Fraternity's disciplinary hearing, (Court reporting) no ink is actually coming out of her pen as she writes on her notepad. That is, the notepad remains blank even as she turns to a new page while writing. (01:04:50 - 01:05:55)
Revealing mistake: On the day the house is being emptied, after Bluto finishes the Jack Daniel's and tosses the bottle, there are no Jack Daniel's labels on it. (01:07:35)
Revealing mistake: When the people from the grandstand are flying up in the air after the Deathmobile hits it, you can tell they used a trampoline to get the effect as the woman are in their stocking feet; it would have been a safety issue if they jumped in high heels.
Revealing mistake: You can see that the Jack Daniels that Bluto chugs is not real, because it foams. It was probably iced tea or something. (01:07:30)
Revealing mistake: During the scene where the Delta boys are looking at slides of the recruits from the evening, Otter steps in front of the screen to defend Flounder. Notice that he is standing directly in line with the projector to the screen and there is no shadow on the screen nor is part of the slide projected onto his chest. (00:14:10)
Revealing mistake: When Bluto first watches the sorority girls on his ladder, he moves to the left screen. As he is moving the ladder, the curtain in front moves too. The glass pane is not present, likely to prevent reflection of the camera.
Answer: He's in R.O.T.C. The Omegas are in the class, too. Military uniforms are required dress.
Captain Defenestrator